The present invention relates to a method for the formation of a transport unit.
Prior known from, for example, U.S. Pat. Nos. 4 113 122, 4 425 071 and 3 471 047 and CH patent specification No. 512 346 are equipment and methods for loading a truck or a trailer with stuff carried on forklift pallets or any appropriate platforms either to fill the entire cargo space or a part of it at a time. Also prior known are equipment and methods based on the utilization of various ball or roller delivery beds or tracks, air cushion elements and sliding surfaces, for example, in loading the platform of a truck or a container. These latter methods and equipment have been disclosed, for example, in FI patent application No. 1069/67 and CH patent specification No. 624 361. In addition to the methods described in the above publications, there are available unloading and loading methods for the cargo space of a truck based on a so-called "walking floor" solution made from aluminum strips and on an endless, cargo space-covering conveyor belt whose winding gear is fitted beneath the cargo space. U.S. Pat. No. 3 578 184 discloses a method and apparatus for effecting the unloading and loading of the covered cargo space of a truck at a loading platform by utilizing sets of rollers that are either fixedly installed or can be elevated from platform level.
The prior known methods and equipment are solutions relating exclusively to the cargo spaces of a truck and have often been based on the transport and handling of a special cargo. They are also characterized by the fact that a cargo space carries along expensive cargo unloading and loading gear, extra equipment facilitating cargo handling or by the fact that for proper operation they require specially designed loading and unloading platforms. The methods and equipment are mostly not at all applicable to a large unit cargo shifting from one transport vehicle to another or, for example, the shifting of a true trailerful from a truck to a train or vice versa.
The above leads to a high basic investment bound to a transport vehicle and, furthermore, in some respects the introduction is limited by high terminal investments.
In the prior known methods, almost without exception, the transported dead weight is increased; the on-going handling equipment, doubled load-bearing structures. In addition to the expensive basic investment, this leads to increasing operating costs.
The prior known methods are primarily intended for handling or carrying either individually packed, box-like bulk cargo, a great volume/weight ratio, or for carrying some other cargo loaded on various forklift plallets or the like. Outside the cargo space, cargo is conventionally handled as boxes or the like or as forklift pallets and the like. The problems involved in intermediate storing and reloading remain unsolved which is an essential drawback, for example, for international traffic, in which a major cargo unit; a semi- or true trailer, a container, a railway car and the like; must often be intermediately stored either as such or in unloaded condition, loaded aboard a ship and reloaded on a new land transport vehicle at the port of destination.
In the transport of paper, for example, a particular problem today in the handling of rolls of paper is a frequent gripper handling of individual rolls. At the mill and in various stages of a modern transport sequence, the rolls are carried from one transport sequence to another by grabbing a roll with hydraulic grippers fitted to a forklift for squeezing the roll therebetween to facilitate a rather short forklift transfer from one place to another. For example, when unloading rolls from roofed railway cars and when transferring them to an intermediate storage, the presentday practice must often involve two handlings with grippers; a so-called low-masted forklift is used to pick up the rolls out of a railway car one by one to be carried by a larger forklift from loading platform to intermediate storage generally 2 to 4 rolls at a time. The intermediate storage is generally a covered, uninsulated warehouse in the harbor or immediately close by. The rolls are stored on top of each other on the floor.
With today's technique, during the transport of a roll from paper mill to intermediate storage in an export market area, the roll must be contacted 6 to 8 times depending on the types of ships used. Every gripper engagement is a potential cause of roll damage. In addition, transfers of one or 2 to 4 rolls tie in each stage a substantial amount of machinery and labor, which also considerably increases indirect costs; spare parts, maintenance, space and personnel. This requirement caused by paper transport for the machinery of ports is of prime importance at several ports since paper is quantitatively a dominating transit article.
Another drawback in the present techniques is that, due to the statutes and regulations in many countries, a fully loaded 40 ft container cannot be driven on roads because of weight limits. The dead weight of such a container is too high for it to be loaded completely.